使用16位浮点纹理保存缓冲区

Question

我找不到使用float的参数组合（我设法用无符号字节保存）：

float *rawImagePixels = (float*)malloc(width * height * sizeof(float));
glPixelStorei(GL_PACK_ALIGNMENT, 4);
glReadPixels(0, 0, width, height, GL_RED_EXT, GL_HALF_FLOAT_OES, rawImagePixels);
NSData *data = [NSData dataWithBytes:rawImagePixels length:width*height];
CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceGray();
CGImageRef iref = CGImageCreate(width, height, 16, 16, width, colorspace, kCGImageAlphaNone|kCGBitmapByteOrder16Big, provider, NULL, NO, kCGRenderingIntentDefault);
UIImage *myImage = [UIImage imageWithCGImage:iref];
UIImageWriteToSavedPhotosAlbum(myImage, self, nil, nil);

我的纹理是一个单通道半浮动纹理。如何将其保存为UIImage？

Answer 1

摘自问题

我用这个代码得到了半像样的结果：

GLhalf *rawImagePixels = (GLhalf*)malloc(width * height * sizeof(GLhalf));
glPixelStorei(GL_PACK_ALIGNMENT, 2);
glReadPixels(0, 0, width, height, GL_RED_EXT, GL_HALF_FLOAT_OES, rawImagePixels);
NSData *data = [NSData dataWithBytes:rawImagePixels length:width * height * sizeof(GLhalf)];
CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceGray();
int bitsPerComponent = 16, bitsPerPixel = 16, bytesPerRow = width * 2;
CGImageRef iref = CGImageCreate(width, height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorspace, kCGImageAlphaNone|kCGBitmapByteOrder16Little, provider, NULL, NO, kCGRenderingIntentDefault);
UIImage *myImage = [UIImage imageWithCGImage:iref];
UIImageWriteToSavedPhotosAlbum(myImage, self, nil, nil);